The element that would have properties most similar to the new element would be an element that lies in the same group as the new element. Specifically, the element with the most similar properties will lie directly above or below that element in the group.
Lanthanides have properties similar to Cerium
No other element has the exact same properties as sodium, but the three with the most similar properties would most likely be lithium, potassium, and rubidium.
The newest officially discovered elements are Ununquadiumand Ununhexium so, we'll focus on those.Ununquadium will be part of the Carbon series, so we would expect it to have properties similar to those elements (e.g. 4 electrons in the outer shell). The closest relation to it in that group would be Lead.Ununhexium will be part of the Oxygen series, so, again, we would expect it to have properties similar to those elements (e.g. 6 electrons in the outer shell). The closest relation to it in that group would be Polonium, which is also the first radioactive element.
Ar
The element with chemical properties most like silicon is germanium. As an example, both are used in semiconductors.
Lanthanides have properties similar to Cerium
Buttholes
No other element has the exact same properties as sodium, but the three with the most similar properties would most likely be lithium, potassium, and rubidium.
lanthanum and other lanthanides
Element A and element B are the most likely to have similar properties because they belong in the same family, because if you know an element's family you can tell the number of valance electrons and the elements they react with. In periods, the properties are not alike, they slowly change in a pattern.
The newest officially discovered elements are Ununquadiumand Ununhexium so, we'll focus on those.Ununquadium will be part of the Carbon series, so we would expect it to have properties similar to those elements (e.g. 4 electrons in the outer shell). The closest relation to it in that group would be Lead.Ununhexium will be part of the Oxygen series, so, again, we would expect it to have properties similar to those elements (e.g. 6 electrons in the outer shell). The closest relation to it in that group would be Polonium, which is also the first radioactive element.
Ar
The two elements that have the most similar chemical properties to arsenic are Phosphorus (P) and Antimony (Sb).
The element with chemical properties most like silicon is germanium. As an example, both are used in semiconductors.
That would be the noble gases
Mg (magnesium)
the most important properties in an element is state at room tempreture